Photographic and imaging systems are primarily designed for use in creating two-dimensional images. In a two-dimensional image, only one perspective is needed. Human vision, however, views scenes from two perspectives with one perspective provided by each eye of an observer. The parallax that exists between the perspectives is interpreted by the mind of the observer to provide depth information about the scene being viewed. Various electronic and photochemical imaging techniques have been developed that capture images of a scene taken from different perspectives. These images are later processed and displayed to a user so that one eye of an observer is exposed to an image of the scene from one perspective, while the other eye of the observer is exposed to another image taken from another perspective. This creates the parallax difference needed to create the appearance of depth in the mind of the observer.
In all multi-perspective imaging systems, the apparent depth in the scene is proportional to the extent of the parallax-induced differences between the presented images. The extent of such parallax-induced differences is determined in part by the degree of separation between the captured images and in part by the distance from the captured images to the scene. Typically, depth imaging systems combine images that are captured at generally the same distance from the scene. This simulates the way that the eyes of a human observer will see a scene. Accordingly, the apparent extent of depth in the resultant output is typically modified by varying the degree of separation between the captured images. This creates an important issue for a photographer in preparing a multi-perspective image: the challenge of selecting the proper combination of images needed to provide a desired depth effect.
In some cameras and photography methods, this challenge is met by the use of cameras that have a fixed separation between the images and thus, the perspective is pre-selected. For example, it is known to capture stereoscopic and depth images using cameras having multiple image capture systems to record multiple images of a scene. See for example, commonly assigned U.S. Pat. No. 6,271,876 entitled “Using Two Different Capture Media to Make Stereo Images of A Scene” filed by McIntyre et al. on May 6, 1997. See also U.S. Pat. No. 4,967,276 entitled “Apparatus for Formatting and Viewing a Stereoscopic Video Frame” filed by Gallaher. Alternatively, it is known to use a camera that provides a single optical path and that is moved along a fixed track. See also U.S. Pat. No. 5,883,695 entitled “Method and Apparatus for Producing Stereoscopic Images with Single Sensor” filed by of Paul on Sep. 19, 1997. See also U.S. Pat. No. 5,325,193 entitled “Single Camera Autostereoscopic Imaging System” filed by Pritchard on Oct. 20, 1992. In such systems, different perspectives are captured as the camera is moved to fixed locations along the path.
Another invention uses a way of adjustable parallax by giving the operator an indication of the separation of the left and right images. See U.S. Pat. No. 7,466,336 entitled “Camera and Method for Composing Multi-Perspective Image”. In this system a capture device contains a mode switch which converts from mono to stereo image capture. This requires a special capture device with a mode switch which is an added expense and an inconvenience.